The present invention relates to the general field of electrical breaker gear, and more particularly to systems enabling breaking to be actuated in this type of gear.
This type of installation comprises one or more electrical breaker poles such as trippable switch-disconnectors, trippable fused switch-disconnectors, trippable switches, and circuit breakers. The main functions of such poles are the following:
setting up and interrupting electric currents on load, on overload, and on short circuits;
protecting a site and personnel against electrical risks; and
guaranteeing user safety (actuation, lockout, and isolation).
Electrical breaker gear is fitted with a control system connected to the electrical breaker poles and from which breaking of circuit breaking is controlled. The control system constitutes the most important safety element of the installation since it is the control system that determines the level of performance and the reliability of the electrical breaker gear and also provides the interface between a user and the electrical power portion of the electrically powered device(s).
The control system enables the user to changeover the breaker pole(s) to go from an open position (power off) to a closed position (power on) and vice versa, by means of a manual control handle or by means of an electrical control.
Independently of this normal operation (i.e. the user opening and closing breaker gear), the control system must be capable of changing over the breaker poles to go from the closed position to the open position without requiring direct intervention from a user, and regardless of the conditions under which the system is used, such as for example while a retaining force is being applied at the same time to the control handle. Such automatic changeover from the closed position to the open position is used mainly for performing safety functions such as an emergency stop, thermal overload, differential fault, short circuit, etc.
The control systems that are presently available are not suitable for ensuring an automatic changeover from the closed position to the open position in reliable manner, in particular because they do not supply sufficient mechanical energy to enable electrical power breaker gear to be actuated, or they do not satisfy certain major safety criteria such as changing over independently of conditions of use or ensuring high speed for the changeover operation.